Syrian rebels say they plan to seize Damascus International Airport, declaring it a legitimate target in their fight to topple President Bashar al-Assad.

A rebel commander said Friday attacks on the airport are justified because it is being used as a military zone. He said civilians should avoid the area. It was unclear just how close to the airport the battles had reached.

Fighting has intensified in the past week in the southern districts of the Syrian capital and its suburbs.

Suspected Syrian Chemical Weapons

Sarin

Man-made highly toxic odorless, tasteless, colorless nerve agent

Possibly used during Iraq-Iran war

Exposure can be by inhalation, ingestion and skin absorption; people can recover with treatment form mild or moderate exposure

Exposure can be through skin contact or inhalation; people can recover with treatment for mild or moderate exposure

Mustard Gas

Chemical warfare agent that causes skin blisters and mucous membranes

Sometimes odorless, sometimes smells like garlic, onions or mustard

Exposure can be by inhalation, ingestion or skin contact

Vapor released in the air can be carried long distances; exposure not usually fatal

Source: CDC

Earlier Friday, Syrian activists said the army had bombed two Damascus suburbs and increased reinforcements in an effort to try to reclaim territory controlled by rebels.

The Syrian Observatory for Human Rights said the army fired rockets at the rebel-held Daraya and Moadamiah suburbs southwest of the capital. The group said it feared that troops massing on the suburbs' outskirts could be the prelude to an imminent ground assault.

Syrian Refugees by Country

Jordan

448,370

Lebanon

455,665

Turkey

324,770

Iraq

142,395

Egypt

62,032

Source: UNHCR

Also Friday, U.S. Secretary of State Hillary Clinton said American and Russian officials will meet in the next few days to find ways to work together to end the violence in Syria.

Clinton said there was no "breakthrough" during talks Thursday in Ireland with Russian Foreign Minister Sergei Lavrov and special United Nations and Arab League envoy Lakhtar Brahimi. But she said they did agree to form lower-level teams to work with Brahimi on possible ways to end the violence.

Russia and the United States have been on opposite sides of the more than year-long conflict.

Clinton stressed that it is important for any country with influence in the Middle East to explore all possible solutions, because developments in Syria are "increasingly dangerous not only to Syrians, but to their neighbors."

Meanwhile, U.S. Defense Secretary Leon Panetta said intelligence shows Assad may be considering using chemical weapons, as rebel successes in the civil war put increasing pressure on his government.

The White House has warned Assad that using chemical gas against his own people would be a "red line" for the United States and bring serious consequences.

United Nations Secretary-General Ban Ki-moon said Friday using such weapons would be an "outrageous crime."

Syrian Deputy Foreign Minister Faisal Maqdad has told Lebanese TV that if Syria had chemical weapons, it would not use them against the Syrian people. He said the West is using the threat of chemical weapons as an excuse to intervene.

U.S. Secretary of State John Kerry has told his Russian counterpart, Sergei Lavrov, that his country could face further consequences to what he called its “already strained economy” if Moscow does not fully comply with a cease-fire in Ukraine. The two met, on Monday, on the sidelines of a U.N. Human Rights Council meeting in Geneva, where Kerry outlined human rights violations in Russian-annexed Crimea and eastern Ukraine. VOA State Department correspondent Pam Dockins reports from Geneva.

Video

U.S. Secretary of State John Kerry has told his Russian counterpart, Sergei Lavrov, that his country could face further consequences to what he called its “already strained economy” if Moscow does not fully comply with a cease-fire in Ukraine. The two met, on Monday, on the sidelines of a U.N. Human Rights Council meeting in Geneva, where Kerry outlined human rights violations in Russian-annexed Crimea and eastern Ukraine. VOA State Department correspondent Pam Dockins reports from Geneva.

Video

Diagnosing infections such as HIV requires expensive clinical tests, making the procedure too costly for many poor patients or those living in remote areas. But a new technology called lab-on-a-chip may make the tests more accessible to many. VOA’s George Putic reports.

Video

Afghan officials have expressed concern over reports of a crackdown on Afghan refugees in Pakistan following the Peshawar school attack in December. Reports of mass arrests and police harassment coupled with fear of an uncertain future are making life difficult for a population that fled its homeland to escape war. VOA’s Ayesha Tanzeem reports from Islamabad.

Video

Despite the ongoing ceasefire in Ukraine, soldiers in the city of Mariupol fear that pro-Russian separatists may be getting ready to attack. The separatists must take or encircle the city if they wish to gain land access to Crimea, which was annexed by Russia early last year. But Ukrainian forces, many of them volunteers, say they are determined to defend it. Patrick Wells reports from Mariupol.

Video

As low oil prices and Western sanctions force Russia's economy into recession, thousands of Moscow restaurants are expected to close their doors. Restaurant owners face rents tied to foreign currency, while rising food prices mean Russians are spending less when they dine out. One entrepreneur in Moscow has started a dinner kit delivery service for those who want to cook at home to save money but not skimp on quality. VOA's Daniel Schearf reports.

Video

The United States and Cuba say they have made progress in the second round of talks on restoring diplomatic relations more than 50 years after breaking off ties. Delegations from both sides met in Washington on Friday to work on opening embassies in Havana and Washington and iron out key obstacles to historic change. VOA’s Mary Alice Salinas reports from the State Department.

Video

One after another, presumptive Republican presidential contenders auditioned for conservative support this week at the Conservative Political Action Conference held outside Washington. The rhetoric was tough as a large field of potential candidates tried to woo conservative support with red-meat attacks on President Barack Obama and Democrats in Congress. VOA Political Columnist Jim Malone takes a look.

Video

New Yorkers take pride in setting world trends — in fashion, the arts and fine dining. The city’s famous biannual Restaurant Week plays a significant role in a booming tourism industry that sustains 359,000 jobs and generates $61 billion in yearly revenue. VOA's Ramon Taylor reports.

Video

Issues like the Keystone XL pipeline, fracking and instability in the Middle East are driving debate in the U.S. about making America energy independent. Recently, the American Energy Innovation Council urged Congress and the White House to make expanded energy research a priority. One beneficiary of increased energy spending would be the Brookhaven National Lab, where clean, renewable, efficient energy is the goal. VOA's Bernard Shusman reports.

Video

There has been a surge of interest in the American civil rights movement of the 1950s and '60s, thanks in part to the Hollywood motion picture "Selma." Five decades later, communities in the South are embracing the dark chapters of their past with hopes of luring tourism dollars. VOA's Chris Simkins reports.

Video

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.

Video

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.